1. Field of the Invention
The present invention relates to the art of welding, and is particularly concerned with a method of depositing a metal other than aluminium onto aluminium-base alloy.
The invention is particularly useful in the manufacture of internal combustion engines for transport vehicles, aircraft and marine engines, and stationary engines, as well as in the aircraft industry and rocket building.
Aluminium-base alloys are used in all the above-mentioned industries. An ever increasing power of such engines requires that alloys used in the manufacture thereof have a correspondingly higher resistance. One of the additional requirements that the engine parts and assemblies which are designed to take up high loads and at the same time are subjected to impact loads at elevated temperatures, must meet is a wear resistance. However, to further improve the wear resistance of parts made from aluminium alloys to meet given operating conditions, it becomes necessary to increase the content of the alloying elements to an extent that will not allow such parts to be manufactured by applying conventional methods such as casting, forging, and stamping. In this respect the deposition of a layer of a metal having a higher wear resistance seems to be the most suitable method of strengthening such parts. However, the scope of practising of the welding techniques with respect to welding aluminium alloys are also limited since adding great amounts of alloying elements to the metal being deposited is not possible to accomplish by applying known in the art processes.
2. Prior Art
There is known a method of depositing a layer of a metal other than aluminium onto aluminium-base alloy with the use of a composite aluminium wire reinforced with fine (0.2 mm) nickel filaments (cf. N. D. Nikitin, A. N. Shalai, Ju. A. Vasiliev "Ispytanie aluminievyh porshney dizeley s iznosostoikoy naplavkoi", M., NIIInformtiyzhmash, 1977).
The above method, however, does not ensure a uniform distribution of nickel in the layer being deposited, which affects the wear resistance of the resulting product. Furthermore, it has a low efficiency; speed of deposition does not exceed 16-20 m per hr. In addition, to apply this method the articles being treated have to be preliminarily heated to a temperature of 200.degree. C., which makes more difficult handling hot articles and requires additional equipment. It should also be noted that the process of manufacturing composite wire is a rather complicated one and is carried out at present only under laboratory conditions, which makes the final product too costly.
The principal object of the present invention is to provide a method of depositing a metal other than aluminium onto aluminium-base alloy, which allows the operating characteristics of parts made from aluminium-base alloys to be improved.
Another object of the invention is to widen the alloying range aluminium-base alloys.
Still another object of the invention is to provide saving alloying elements which are in short supply, such as nickel and cobalt.
A further object of the invention is to provide a higher efficiency of the process of depositing a metal other than aluminium onto aluminium-base alloys and simultaneously improve the quality of the resulting metal deposit.
Other objects and the advantages of the present invention will become apparent from the reading of the attached specification.